Navfree, a free GPS app available for both iOS and Android has just announced its latest milestone, passing the 5.5 million user mark. Growing at a rate of 500,000 new users per month, this latest figure puts Navfree on equal standing with Nokia’s GPS navigational system.

First launched on Apple’s iOS a couple of years ago, the Android version of the app was released just last month. In that time, it has already managed to clock up 370,000 users.

The way that the Navmii app operates allows users to access its maps, regardless of whether or not the phone has a data connection. This feature makes Navfree an extremely cost-effective GPS option, avoiding hiked mobile data charges.

Navfree’s maps are powered by Openstreetmap, a free, editable and crowdsourced worldwide map. Because users in each town, city or country, are contributing to the map, it gives Navfree the added advantage of realtime updates that reflect the reality on the ground. Navfree sees about 20,000 map corrections made per month, bringing more accuracy to users.

Navfree is not the only app that takes advantage of crowdsourced data to get its users where they want to go. Free GPS app Waze crowdsources traffic conditions, to let users know which route to best take. Waze itself recently achieved an impressive milestone, crossing the 10 million user mark.

Navfree features include turn-by-turn directions, spoken and on-screen instructions, offline map use and address and live search, powered by Google and Bing. Maps are currently available for over 30 countries including the UK, Spain, South Africa, Australia, and India. Navfree is also available on Windows Mobile, Symbian, and as a desktop app for Windows.

Peter Atalla, CEO of Navmii, said: “When we launched the product two years ago I remember people saying that it was impossible to compete with the likes of TomTom and Nokia for satellite navigation on the mobile phones. Two years later Navfree has attracted 5.5 million users, and is ahead of Nokia with a European market share of 8% in mobile GPS navigation.”